[PATCH] drm/format-helper: Fix dst computation in drm_fb_xrgb8888_to_rgb888_dstclip()

From: Hector Martin
Date: Wed Nov 17 2021 - 09:23:35 EST


The dst pointer was being advanced by the clip width, not the full line
stride, resulting in corruption. The clip offset was also calculated
incorrectly.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
drivers/gpu/drm/drm_format_helper.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index e676921422b8..12bc6b45e95b 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -366,12 +366,12 @@ void drm_fb_xrgb8888_to_rgb888_dstclip(void __iomem *dst, unsigned int dst_pitch
return;

vaddr += clip_offset(clip, fb->pitches[0], sizeof(u32));
- dst += clip_offset(clip, dst_pitch, sizeof(u16));
+ dst += clip_offset(clip, dst_pitch, 3);
for (y = 0; y < lines; y++) {
drm_fb_xrgb8888_to_rgb888_line(dbuf, vaddr, linepixels);
memcpy_toio(dst, dbuf, dst_len);
vaddr += fb->pitches[0];
- dst += dst_len;
+ dst += dst_pitch;
}

kfree(dbuf);
--
2.33.0